Systems and methods for determining gas turbine engine operating margins

A method for determining an engine operating margin for an engine parameter of a gas turbine engine for an aircraft, the method comprising:

• identifying a current engine installation configuration for the gas turbine engine and the aircraft;
• determining an expected normalized value of the engine parameter based on the current engine installation configuration and one or more of a normalized engine power (SHPN) of the gas turbine engine, an engine inlet temperature, an airspeed, or an altitude;
• determining a fully deteriorated engine (FDE) value of the engine parameter using the expected normalized value of the engine parameter;
• determining a current value of the engine parameter for the gas turbine engine;
• and
• determining the engine operating margin for the engine parameter based on the FDE value of the engine parameter and the current value of the engine parameter;
• determining a scaling factor based on SHPN, altitude, current ISA deviation, and the current engine installation configuration;
• and
• applying the scaling factor to the expected normalized value of the engine parameter.

A gas turbine engine for an aircraft, the gas turbine engine comprising:

• an air inlet;
• a first rotational assembly including a first shaft, a bladed first compressor rotor, and a bladed first turbine rotor, the first shaft interconnecting the bladed first compressor rotor and the bladed first turbine rotor;
• a second rotational assembly include a second shaft, a bladed second compressor rotor, and a bladed second turbine rotor, the second shaft interconnecting the bladed second compressor rotor and the bladed second turbine rotor;
• an exhaust section,
• wherein air inlet, the first rotational assembly, the second rotational assembly, and the exhaust section form a core flow path of the gas turbine engine;
• and
• an engine control system including a processor in communication with a non-transitory memory storing instructions, which instructions when executed by the processor, cause the processor to:
• obtain a current engine installation configuration for the gas turbine engine and the aircraft;
• determine an expected normalized value of the engine parameter based on the current engine installation configuration and one or more of a normalized engine power (SHPN) of the gas turbine engine, an engine inlet temperature, an airspeed, or an altitude;
• determine a fully deteriorated engine (FDE) value of an engine parameter of the gas turbine engine using the current engine installation configuration;
• determine a current value of the engine parameter for the gas turbine engine;
• and
• determine an engine operating margin for the engine parameter based on the FDE value of the engine parameter and the current value of the engine parameter;
• determine a scaling factor based on one or more of SHPN, altitude, current ISA deviation, and the current engine installation configuration;
• and
• apply the scaling factor to the expected normalized value of the engine parameter.